Connection plug



May 26, 1925.

F. E. PETRI CONNECTION PLUG Filed Feb. 4, 19,24

Ja /5121a:

Patented May 26, 1925.

UNITED rates FRANK n rn'rar, or rnonIA, ILLINOIS.

CONNECTION PLUG.

Application filed February 4,1924. Se'rial No. 690,438.

invention residing in the plug which forms a part of the means forconnecting or-disconnecting 'the' current supply.

One object "of my invention is the provision o l a heavy duty plugwhich,while not intended to carry an excessive current, is constructed towithstand hard and continuous service.

Another obiect of my invention is the provision of means whereby whenthe plug is-operated to connect or disconnect a current supply, thewires which are attached to the plug are not twisted or untwisted duning the connecting or disconnecting operation.

Another object of my invention is the construction and arrangement ofparts whereby when the plug is screwed down into the socket, properelectrical connections between the parts are assured.

Other objects or" my invention, and the novelty thereof will behereinafter more fully set forth and speii-ifically pointed out in theclaims.

In the accompanying drawing:

Fig. 1 is an elevation of my plug completely assembled.

Fig. 2 is a sectional elevation of Fig. 1.

Fig. 3 is a View of the major parts of the device disassembled.

The same numerals of reference are used to indicate identical parts inall the figures.

My plug consists primarily of three major portions, an insulating handleportion 4, a threaded portion 5, and an insulated ter minal portion 6.As shown more clearly in Fig. 2 the portion 4 carries a metal ring 7which carries a pair of screws 8, the latter passing through suitableopenings in the side of the portion 4, this portion being centrallyapertured as at 9 to permit the wires or conductors topass-through it.The threaded portion 6' is turned inwardly at its lowerendas shown at10, and its upper end is provided with bayonet joint slots '11 to beengaged by the -screws 8. The terminal portion '6 whichis preferablymade 'of porcelain or other suitable insulating material is providedwith a contact screw and was-her 12, between which and the "base 13therefor one of the wires is clamped, the base 13 being held in place bya'tubular rivet 1a through which the wire p'asses, this constructionbeing similar to "corresponding parts of the ordinary connection plug.

The upper portion of the terminal portion 6 is surrounded by -a metalband 15 which carries a binder '16 to which theether wire for-thecircuit is attachedi the band '15 being shaped to engage the innersurface and a portion of the lower'en'd of the nnetal ring 7. i 1 I henassembled as'inFig. 2, the terminal portion 6 is held in place byltheinturned portion 10 of thethreaded portion 5-COIl1i112,'

in contact with. the shoulder 16 formed near the lower end of the member6, though the member 6 is free to turn in the assembled structure to theend that the portions 4 and 5 may be turned about it when making theconnection. I As soon as the plug has been screwed into the socket to apoint where the screw and washer 12 come in con tact with the centerconnection of the sock et, the portion 6 is forced upward with relationto the balance of the plug to cause the metal ring 15 to engage with thering 7 and make a proper electrical connection between the two, thusestablishing a circuit from the threaded sleeve 5, through the ring 7 tothe band 15 and binder 16, the tightness of this connection beingdetermined by the pressure produced by the threaded portion 5.

The plug may be readily disassembled by loosing the screws 8 anddisengaging the bayonet connection between these screws and the threadedportion 5, whereupon the terminal portion 6 may be removed from thethreaded portion 5, to enable the wires to be properly connected totheir respective points, it being remembered that the wires are firstthreaded through the hole 9 of the insulator 4, and then connected tothe binders of the terminal portion 6 after which the portion t isbrought below the surface of the insulating portion 4 to preclude thepossibility of touching them with the finger so that there is nolikelihood of the user coming in contactwith any of the live connectionsduring attachment or detachment of the plug.

By placing the bayonet joint slots 11, and forming them to lead in thedirection of the threads of the portion 5, the plug will not come aparteven though the screws 8 are not properly tightened and when the plug isattached to a socket the action of the thread engagement will pull theportion 5 downward with relation to the rest of the plug and soestablish agood connection between the screws 8 and the slots 11.

It is to be noted that when the plug is screwed into the socket, thepressure exerted by the engagement of the threads serves to tighten'andhold in place all of the electrical connections, and further that thepresv threaded sleeve portion provided with bayo- 1 net joint connectingmeans cooperating with the contact ring, a terminal carrying portionretained in place by the threaded sleeve portion, acontact band carriedby the terminal contact portion cooperating with the-r contact ring ofthe insulated handle portion when the plug is attachedv to a socket. o

2. In an attachment plug the combination of an insulating handleportion, a reinforcing and contact ring imbedded therein, screwscarried. by said ring, a threaded' sleeve portion for engagement withthe socket, bayonet joint slots for engagement with the screws of thecontact ring, a terminal carrying portion loosely mounted in thethreaded sleeve portion and carrying a central contact at one end and acontact band at the other end to cooperate with the con tact ring of thehandle ortion.

FR NK E.PETRI,

